The EIA method has been used recently as a method to measure immunity using the antigen-antibody reaction, as known in the prior art.
The reaction of the EIA method is so sensitive and accurate that the method is used to analyze, for example, CEA, Fer, .beta..sub.2 -M, IgE, TSH, T.sub.3, T.sub.4, AFP, CA-50, etc.
Such EIA method as described above is classified into the beads EIA method and coating EIA method, etc. as known in the prior art; in the former, antibody is sensitized on the surface of spherical beads while it being coated on the wall surface of cells in the latter.
However, in these EIA methods known in the prior art, it is required to add an antibody non-solution, stroma solution, reaction stop solution, etc. in time according to the progress of reaction. Such a work of adding them is much complicated. Moreover, the reaction time of such an inspection is so long as a long time is spent until a final inspection result is available. These problems associated with conventional EIA methods are disadvantageous for practical applications.